A quick introduction on REST and Dropwizard for Bucharest Java User Group 5 - http://bjug.ro/

1. Simple REST with
Dropwizard
Intro, Structure, Resources, Deployment
Bucharest JUG #5 @ Cegeka

2. Andrei Savu
Founder @ Axemblr.com
Apache Whirr PMC member
jclouds committer
Connect with me on LinkedIn

3. Disclaimer
Highly Technical, Opinionated Talk

4. REST
(Representation State Transfer)
Browser Analogy: Fetch representation of the
current state of a resource (page)
Makes extensive use of HTTP semantics

5. Resource & Representation
Resource = the real thing
Representation = server responses
"A request interacts with a resource and
receives a representation."

6. REST Verbs
Match HTTP semantics:
● GET : read resources, safe, cache friendly
● POST : update resources, create
● PUT : replace entire resource, atomic
● DELETE : delete entire resource, atomic
● HEAD
● PATCH

7. REST Batch Operations
A request can act on a single resource or a
class of resources.
E.g.
POST /todos/1 {'email', 'new@example.com'}
POST /todos?email=x {'email': 'other@x.com'}

8. REST Transport
HTTP
With representations as JSON or XML
Negotiation with Accept & Content-Type
headers
Supports caching, If-Modified-Since queries

9. Architectures #1
Web UI
Database
API

10. Architectures #2
Web UI
API Database
Mobile

11. Architectures #3
Web UI Database
Internal
API Platform Queues
APIs
Mobile Other

12. Dropwizard
Thanks Yammer (Coda Hale) for making it
open source!
Framework for JVM-based backend services
"Dropwizard has out-of-the-box support for sophisticated configuration,
application metrics, logging, operational tools, and much more, allowing you
and your team to ship a production-quality HTTP+JSON web service in the
shortest time possible."

13. Components
● Jetty for HTTP
● Jersey for REST
● Jackson for JSON
● Metrics for metrics
● And: guava, logback, hibernate validator,
jersey client libraries, jdbi, freemarker
http://dropwizard.codahale.com/getting-started/

14. Demo Application
Structure, Configuration, Deployment

15. Specification
"A simple todo list sample application implemented using
Dropwizard as the core framework with a simple UI that
consumes the REST API based on twitter bootstrap,
backbone.js, jquery and jasmine."
https://github.com/bucharest-jug/dropwizard-todo

16. REST Endpoints
GET /todos | GET /todos/{id}
POST /todos
PUT /todos/{id}
DELETE /todos | DELETE /todos/{id}

17. Resources: Todo List
● id : assigned by server on creation (Read
Only)
● created : assigned on creation
● email: owner email address
● items: list of items

18. Resources: Todo Item
● title: a text description of what need to be
done
● created: date time assigned on creation
● finished: date time assigned when the item
was finished

19. To the IDE!
Structure, Configuration, Testing

20. Production Configuration
Dedicated repository with restricted access.
Cool tool: etckeeper (debian)

21. Deployment: Start Simple
Run tests on the local machine
Fabric / Capistrano
Supervisor / Upstart
Monit
Ganglia / Nagios / Cloudwatch / SNS

22. Deployment: Automate
Continuous Integration
Puppet / Chef
1-step deployment from a specific branch
Ability to rebuild from a vanilla OS install
Leverage cloud infrastructure for Dev & QA

23. Deployment: Continuous
High quality test suite (unit + live + smoke)
Continuous Deployment Pipeline
All new code is deployed to multiple
environments and production.
OpenAgile Timisoara anyone?

24. Resources
● Demo code:
https://github.com/bucharest-jug/dropwizard-todo
● All about Dropwizard:
http://dropwizard.codahale.com/
● API Grove: API management:
http://apigrove.net/

25. Thanks!
asavu@apache.org